Jump to content

Twin cam head design


mikuni

Recommended Posts

At risk of sounding like a broken record : If I had my time again I would purchase a Honda S2000 motor and gearbox, smack it into my Cortina factory standard, change the oil and go racing.

Funny you should say that again. I was looking through the SS2000 forum today and they were talking about putting an F20C (S2000) motor that makes sweet sweet power, up to a K20A (the front wheel drive engine) gearbox if you want to do a FWD car. Gives a better engine with more power.

Then looked up a few different build threads etc. Those things really are works of art. The valve train and price of parts when they go bang scares the living crap out of me though. One guy spent close to $5k just on parts for an original rebuild. Didn't replace pistons, just pumps, bearings etc

Still.....

0609turp_20z+honda_f20c_stroker_build+engine_block.jpg

Link to comment
Share on other sites

  • Replies 124
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

At risk of sounding like a broken record : If I had my time again I would purchase a Honda S2000 motor and gearbox, smack it into my Cortina factory standard, change the oil and go racing.

Funny you should say that again. I was looking through the SS2000 forum today and they were talking about putting an F20C (S2000) motor that makes sweet sweet power, up to a K20A (the front wheel drive engine) gearbox if you want to do a FWD car. Gives a better engine with more power.

Then looked up a few different build threads etc. Those things really are works of art. The valve train and price of parts when they go bang scares the living crap out of me though. One guy spent close to $5k just on parts for an original rebuild. Didn't replace pistons, just pumps, bearings etc

Still.....

0609turp_20z+honda_f20c_stroker_build+engine_block.jpg

fuck me thats solid :| .. goes towards the 9.5 limit though i spose

Link to comment
Share on other sites

Yeah, the going rate for an F20C is about the same as a well prepared race engine of other varieties, but is also has similar power to a well built 2L as well. So you get a fast motor with the option of making it faster later on. The cheapest I've seen a conversion go for lately was $10k, and an f20c motor and box would set you back about the same.

it'd be interesting to see the head layout of an F20c, a cross section of ports and view of valve angles to compare to the others posted in this thread.

Link to comment
Share on other sites

interesting this topic has come up. maybe slightly off topic, but maybe of interest... have been doing quite a bit of testing with a home made flow bench and an old smallport 4age head. have tried taking material out of the ports in various places, with not alot of luck. mostly making the flow worse. very easy to completely wreck the flow, with a small amount removed from the wrong place. as everyone has said the short radius has a huge effect on flow.

going back to a stock port, i managed to loose basically zero flow filling from the port entry to the port divider. at one point the port is 30-40% (rough guess) smaller than standard. plan is to gain velocity without loosing too much flow.

the epoxy setting on the proper head at the moment. will take some pics over the next few days once ive shaped it.

Link to comment
Share on other sites

Best I can do:

This is K20

04_02.jpg

And an F20

p87367_large+2000_Honda_S2000+engine_Cut_Away.jpg

Some gay things I have found on the Honda engines, apart from expensive of the parts and the complexity, they seem to have a couple of flaws. A weak oil pump in the early gen engines and the cam chain goes down into the sump?!

Also power. The car makes 247hp apparently but the highest dyno figure I have found from an F20C on a dyno factory standard is 207hp at the wheels. Thats quite a bit lower really, would be hard to explain that missing 40hp in losses no matter who you are. Several were around the 200hp at the wheels while I found some as low as 186hp but ofcourse dynos are pretty rough guides so I'm not focusing too much on those figures. Just interesting to see some real world stuff, not just factory quoted numbers for a change.

People do seem to be able to get about 10% more out of them but no shit, it takes throttles, cams aftermarket management, headers, exhaust system and all that only brings it up closer to the 240rwhp mark. Its common for mods to actually detune these engines and for me, the whole point of building something is to be able to play with it for little gains, like what KPR does, not be too worried to touch it for fear that your $10,000 might loose more power.

Also, just for the infomation of you guys. Heres a link to one of the main Vauxhall tuners in the UK. Off the shelf anything, you can even get kits for 225,230,250,270+ and 290+ engines where they supply everything you need, even a CNC and hand ported head, dryp sump, crank, pistons, and an alloy block if you want to save 16kg. All for ~$30,000. Crazy, but still not rediculous money for a pretty rediculous NA engine.

http://www.sbdev.co.uk/Main.htm

Link to comment
Share on other sites

Interesting. 200rwhp isn't that much? Don't they make that sorta power at the wheels out of tuned B series?

Talking about ports, take a look at this - BMW K1200RS motorbike head. I'm putting one of these on my mini - they are supposed to flow really well. 165fwhp out of a 1380cc well with standard itb's and cams (although stock cams are around 280deg duration). Apparently totally driveable too, give nice power everywhere. Should be a nice upgrade from the iron 5-porter.

Inlet port looks pretty good and has lots of meat for playing around with. BMW supposedly had 200hp out of them on their 1200cc K-bikes during testing, and detuned them back to 130ish for reliability/rideability.

4217.jpg

Link to comment
Share on other sites

Quoted for more truth

also - real example

http://forums.turbo124.com/viewtopic.php?t=5768

At risk of sounding like a broken record : If I had my time again I would purchase a Honda S2000 motor and gearbox, smack it into my Cortina factory standard, change the oil and go racing.

It would be much cheaper, much faster and much more reliable than what I am currently doing (but not Pre65 legal of course).

This man speaks the truth

There got to be a reason that the brown datsun that owns the ss2000 series runs a basically stock s2k motor, I belive they did put some TODA cams into the engine but couldn't get anymore form it

It's always best to follow the path well trodden, look at what other have done and improve on there work

Also remeber the manifacture always knows best, there will always be reason as to why a manifacture has done somthing in a particuler way

Remeber they spend $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ creating new motors

Link to comment
Share on other sites

There's no doubt in my mind that the S2K motor/box is the best NA 2 litre package you can get for a RWD car.

But it's what 240hp for $8-9k? for an S2k setup?

Or 210hp for $2-3k or so with an altezza package.

I'm not suggesting it because I've got one, but the altezza setup is definitely the most cost effective $/hp for a reliable 2 litre NA setup that you can wail on all day long.

I would take an F20C over my beams motor any day of the week....

But they're too expensive! And far less common, so a lot harder to replace if need be.

Using standard Altezza block, spending some $$$ on things like nice extractors, ECU and throttles perhaps, and you might be 20hp down on F20C but only spent half as much. And when/if your motor blows up, just go buy another standard block for cheap, put your fancy bits on it, and be up and running again.

Rather than completely up the shit, having to replace an expensive (although admittedly superior) motor, or having a fully built motor that you've spent $$$$ on blow up, which leaves you back at square one.

Link to comment
Share on other sites

Could cost you a fair bit of coin to get decent extractors though, an ecu to run the cam phasing will also cost around 3k+ plus the tuning costs, itbs will also be a fair bit of coin if you can't make the manifold yourself.

You're starting to look very close to f20c prices after all that.

Link to comment
Share on other sites

all depends if you want a project, or just bolt in and thrash kinda thing i guess.

heres the pic of what im doing to my shitty 4age anyway

Pic_0001tinyp.jpg

possibly on the small side at the moment, but not too much drama to pull the head off and change if it sucks

Link to comment
Share on other sites

Could cost you a fair bit of coin to get decent extractors though,

It's a moot point, given that S2k extractors never fit, and run down the right hand side of the car so more of a PITA to remake around steering column etc. Beams motor runs down other side, so easier to make a manifold if you're gonna. But better chances of fitting up sweet in the first place.

an ecu to run the cam phasing will also cost around 3k+ plus the tuning costs

Powerfc!

Plug and play, comes with a good basemap, VVTI fully mapped, ready to suit factory sensors, all setup. A few tweaks on the dyno at best and you'd be good to go.

I bought one for $650 back in the day, but sold it on to fund a trackday. :oops:

I think they're about $1200 brand new.

Or for the single VVTI motors, redtop etc, the powerfc from the 1ZZFE is nearly plug and play, just need 1ZZFE coilpacks, splice oxy sensor wires or something, upload 3S basemap onto it with FC datalogit.

itbs will also be a fair bit of coin if you can't make the manifold yourself.

Also a moot point, as it's equally if not more expensive for S2k quad throttles, and the factory manifolds flow well in either instance.

You're starting to look very close to f20c prices after all that.

Yes, but the point is that even if it costs almost the same, you're still only $1200 or so down the tubes when/if you blow up a motor. Rather than $8k down the hole.

Also, you can get the car up and running with standard power and add bits over time, rather than all eggs in one basket and needing $10k up front for motor and gearbox.

In saying this I've seen a few F20C into AE86 build ups on various forums and some youtube videos, and they sound and look freaken sweet, go really well. Definitely a cool combo!

F20C into FWD would be interesting, wonder if it's been done before.

Link to comment
Share on other sites

all depends if you want a project, or just bolt in and thrash kinda thing i guess.

heres the pic of what im doing to my shitty 4age anyway

Pic_0001tinyp.jpg

possibly on the small side at the moment, but not too much drama to pull the head off and change if it sucks

Looking good man. Any more specifics on how you made your flowbench?

Link to comment
Share on other sites

F20C into FWD would be interesting, wonder if it's been done before.

Pretty sure the Ant Te Rito that has the CRX delsol in SS2000 runs an F20c, and I think the car was built by Mr Strong originally - provided I remembered the conversation right.

Link to comment
Share on other sites

F20C into FWD would be interesting, wonder if it's been done before.

yup, it has been, have seen pics of it done, in the states i think

Been done here too, there's a guy running an ex Dave Strong Del Sol in SS2000 with a FWD F20C.

/should have read earlier post.

Link to comment
Share on other sites

all depends if you want a project, or just bolt in and thrash kinda thing i guess.

heres the pic of what im doing to my shitty 4age anyway

Pic_0001tinyp.jpg

possibly on the small side at the moment, but not too much drama to pull the head off and change if it sucks

Looking good man. Any more specifics on how you made your flowbench?

haha its pretty hori. vacuum cleaner, manometer and some pvc pipes and alot of tape!. worked all good to compare. not produce accurate cfm results

Pic_0007fl.jpg

theres quite a bit of info out there, on how to build a decent one.

http://www.tractorsport.com/cgi-bin/for ... nboard.cgi

http://performancetrends.com/ez_flow_system.htm

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...